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用GD库生成高质量的缩略图片 [复制链接]

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离线cai
 

只看楼主 倒序阅读 0楼 发表于: 2005-01-07
用GD库生成高质量的缩略图片

<?

$FILENAME="image_name";

// 生成图片的宽度
$RESIZEWIDTH=400;

// 生成图片的高度
$RESIZEHEIGHT=400;


function ResizeImage($im,$maxwidth,$maxheight,$name){
  $width = imagesx($im);
  $height = imagesy($im);
  if(($maxwidth && $width > $maxwidth) || ($maxheight && $height > $maxheight)){
    if($maxwidth && $width > $maxwidth){
        $widthratio = $maxwidth/$width;
        $RESIZEWIDTH=true;
    }
    if($maxheight && $height > $maxheight){
        $heightratio = $maxheight/$height;
        $RESIZEHEIGHT=true;
    }
    if($RESIZEWIDTH && $RESIZEHEIGHT){
        if($widthratio < $heightratio){
          $ratio = $widthratio;
        }else{
          $ratio = $heightratio;
        }
    }elseif($RESIZEWIDTH){
        $ratio = $widthratio;
    }elseif($RESIZEHEIGHT){
        $ratio = $heightratio;
    }
    $newwidth = $width * $ratio;
    $newheight = $height * $ratio;
    if(function_exists("imagecopyresampled")){
        $newim = imagecreatetruecolor($newwidth, $newheight);
        imagecopyresampled($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);
    }else{
        $newim = imagecreate($newwidth, $newheight);
        imagecopyresized($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);
    }
    ImageJpeg ($newim,$name . ".jpg");
    ImageDestroy ($newim);
  }else{
    ImageJpeg ($im,$name . ".jpg");
  }
}



if($_FILES['image']['size']){
  if($_FILES['image']['type'] == "image/pjpeg"){
    $im = imagecreatefromjpeg($_FILES['image']['tmp_name']);
  }elseif($_FILES['image']['type'] == "image/x-png"){
    $im = imagecreatefrompng($_FILES['image']['tmp_name']);
  }elseif($_FILES['image']['type'] == "image/gif"){
    $im = imagecreatefromgif($_FILES['image']['tmp_name']);
  }
  if($im){
    if(file_exists("$FILENAME.jpg")){
        unlink("$FILENAME.jpg");
    }
    ResizeImage($im,$RESIZEWIDTH,$RESIZEHEIGHT,$FILENAME);
    ImageDestroy ($im);
  }
}

?>

<img src="<? echo($FILENAME.".jpg?reload=".rand(0,999999)); ?>"><br><br>

<form enctype="multipart/form-data" method="post">
<br>
<input type="file" name="image" size="50" value="浏览"><p>
<input type="submit" value="上传图片">
</form>

</body>
</html>
grant all privileges on *.* to 'a'@'localhost' identified by 'a' with grant option;flush privileges;
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